A few days ago I found my grandfather's old super 8 camera (a Yashica super 825), and I have not idea of how to use it, what cartridge I have to buy and things like that.

So I was looking for information in internet when I reached to your forum, and I think that I could find the help that I need, I want to be a regular super 8 user. For example, I have already found the Wein Cells battery that substitutes old mercury 1.3V batteries.

I think that my most important question is: What cartridges I can use? The camera was with a Kodachrome 40D, but internet says that now is impossible to process it.

Since this camera does auto exposure I'm not quite sure which films will work with your camera currently. Perhaps the Kodak Vision3 50D (negative film)? You might want to wait until Kodak re-releases the Kodak Ektachrome 100D film (hopefully this summer). That film should fit most cameras.

Like Andreas said, Kodak Vision3 50 would work, it will only over expose by about 1 stop, well within the films latitude. This is because Vision 3 is negative film, it will need to be scanned to view it on a computer. If your grandfather left you his projector as well you will want to use Reversal film. With reversal film you will have less latitude so you would want to get film that the camera can meter properly. When they give the daylight/tungsten numbers for what film speed it works with that's because there is a filter inside the camera that will move in front of the lens if you insert a tungsten balanced film. The way it does this is usually by detecting a notch on the film cartridge. Some cameras will have a switch on the camera to manually move the filter. It sounds like your camera detects this automatically since it has the "automatic cancellation with daylight cartridge". There should be a small button next to the film gate where the cartridge seats against. That button moves the filter. Tungsten balanced film will give you correct colors when you film indoors with tungsten lights, daylight film will give you correct colors when you film outside in daylight.